Haricot Beans and Lamb in a Tomato Sauce

• 200 g (7 oz/1 cup) dried haricot (navy) beans
• 40

The day before, soak the beans in a large volume of water. The next day, drain and rinse with fresh cold water. Put the beans in a large saucepan, cover well with water and bring to the boil. Simmer for about 20 minutes. Drain again, cool a little, then remove and discard the loosened skins; set the beans aside. Melt the butter in a large saucepan over medium heat. Add the onion, tomato paste a